In the long term evolution (LTE) system, the 3rd generation partnership project (3GPP) proposes multimedia broadcast multicast service (MBMS), which may transmit data from one data source to a plurality of targets so as to realize sharing of network (including core network and access network) resource and improve utilization rate of network resource (in particular radio interface resource).
Recently, MBMS service is introduced to the LTE R9 system. It needs the common transmission of control signal and user data to realize the carrying of the MBMS service in the system. In this case, the control signal will notify receiver of corresponding control parameters, in which the receiver may be user equipment (UE) or may be called a terminal. And the control signal will direct the UE to receive the MBMS service (corresponding user data) that it is interested in at the corresponding position. The control signal is transmitted via multicast control channel (MCCH) in LTE R9 system.
MBMS service divides area by multimedia broadcast multicast service single frequency network Area (MBSFN Area), wherein the MBSFN Area is formed by a series of cells. The cells in MBSFN Area may use MBSFN technology for synchronous transmission when transmitting the control signal and user data, such that UE may acquire corresponding combining gain during receiving. A specific cell may be covered by a plurality of MBSFN Areas simultaneously, which is generally called MBSFN Area overlapping. Currently, the cell supports overlapping of one to eight MBSFN Areas. When there is overlapping in a specific cell, the cell may have a plurality of MCCHs simultaneously (for each MBSFN Area is corresponding to one MCCH). Each specific MCCH has MCCH modification period (MP), and in the MCCH MP, the content carried by MCCH is not allowed for modification. In MCCH MP, MCCH information transmits repeatedly, wherein the time interval for transmission is called MCCH repeating period (RP). Transmitting repeatedly in repeating period is mainly to improve the reliability of UE receiving MCCH information. FIG. 1 is a diagram of logic relationship of MCCH MP and MCCP RP according to relative technology. As shown in FIG. 1, in MCCH MP (n), the content transmitted by MCCH may not be modified until the next MCCH MP. MCCH MP denotes repeating transmission of MCCH content in MCCH MP. UE can acquire all MCCHs and the corresponding configuration information (for example, how many MCCHs there are in the cell, corresponding parameter of MP, RP of each MCCH) in the cell via a system information block (SIB) 13 of the broadcast control channel (BCCH). UE has known SIB13 in BCCH before preparing to receive MBMS service.
MBMS service is featured in large data amount of service, long duration during terminal receiving and relatively constant average data rate. These features determine that the schedule and control signal configuration of the MBMS service is semi-static, that is to say, the schedule information and control information of the MBMS service keep unmodified “in a long term” such that in each period of MCCH information system side transmits unmodified information (transmitting all the time because new users may access at any time). If the terminal that has acquired MCCH information receives unmodified MCCH information each time, terminal is power-consumptive. For the amount of MCCH information is large, the receiving and analyzing processes are power-consumptive.
In consideration of the above problems, MBMS notification message (called MCCH change notification, or MBMS notification indicator, or MBMS notification information, or MBMS notification in English; also called MBMS notification message, MBMS notification information or MBMS indication information and so on; hereinafter taking MBMS notification message, MBMS notification information in English as example to describe) is introduced. MBMS notification message uses little amount of information to describe whether there is change between the MCCH information that the next MP will transmit and the MCCH information transmitted in the current MP. UE only needs to monitor little amount of MBMS notification message information, and it determines whether to receive coming MCCH information according to MBMS notification message terminal. The specific transmission position of the MCCH notification message is notified by SIB13 in BCCH.
When there is overlapping in the cell, all MCCHs in the cell may use a common MCCH notification to indicate the modification condition of a plurality of MCCHs. Specifically, MCCH notification may indicate which MCCH or MCCHs is or are modified via the payload, wherein the payload of MCCH notification is 8 bits. It transmits in physical downlink control channel (PDCCH) using downlink control information (DCI) Format 1C. MCCH notification supports eight MCCH instructions at most, wherein which bit of MCCH notification represents which MCCH will be notified by SIB13 in BCCH. MCCH notification is transmitted repeatedly in MCCH MP. The transmitting times may be multi times (also may be once). The main purpose of transmitting MCCH information repeatedly in MCCH MP is to improve the receiving reliability.
Currently, the existing problem is that there is a plurality of MCCHs in the cell when there is overlapping in the cell, and the MPs corresponding to each MCCH are different. Thus, UE cannot determine the MCCH notification is received how many times within how long time interval. Therefore, UE may try to receive MCCH notification repeatedly such that the power consumption is large.